One conventional process of forming a colored film on a glass panel employs Ag staining as disclosed in Japanese laid-open patent publications Nos. 56-14454 and 57-95854.
It is also known to employ a lustering solution of a precious metal such as Au or Pd dissolved in rosemary oil to form a colored film according to the screen printing process.
The colored film formed on a glass panel through Ag staining has been disadvantageous in that the colored film tends to suffer color irregularities because the dispersion of Ag somewhat varies depending on the temperature. The colored film is also problematic in practical use since it is poor in wear resistance and acid resistance.
The colored film formed of the lustering solution by the screen printing process is also poor in wear resistance and acid resistance because it is in the form of a foil composed of bonded metal crystals, and suffers a high manufacturing cost because is made of the natural material. Another drawback is that since the colored film produces a metallic luster and has a high reflectance, if the glass panel is used as an automobile glass panel, then it is not preferable from the standpoint of traffic safety due to reflections it produces toward automobiles running behind.